A phase difference plate is widely used as a component of a display device such as a liquid crystal display device. It is preferable that a phase difference plate used in a display device expresses a desired phase difference of λ/4, λ/2, or the like in the entire wavelength region for displaying (usually visible region). In order to express such a phase difference, it is necessary that the phase difference plate has so-called reverse wavelength dispersion, i.e., wavelength dispersion in which anisotropy for light with a long wavelength is higher than that for light with a short wavelength. As a phase difference plate exhibiting reverse wavelength dispersion property, e.g., those described in Patent Literatures 1 to 6 are known.